SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a38acb076d776bfeccbdf9dd628d37ac82530e2cb33f2ac076eb7f815f3254' 
  AND token = 'HoOm58SSFQbuNkerFlaMmrPw4iS+L/zMl2jnzEufbHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}